Here's one for the "How on Earth did nobody think of this before?" files.
Video Star for iOS facilitates the creation of homespun music videos to go along with any song on your device. To use it, you simply choose a song from your music library and start shooting. You can act along with the song, lip sync, dance, shoot video of your dog, or whatever.
Crucially, you can stop shooting at any time. When you start again, the app plays the previous bit of the song before it starts recording, so you can start right up again without the audio and video falling out of sync. Doing that manually would require lots of video editing and general annoyance. This is what technology is for: to sweat the details while we humans just do what we do.
Even better, Video Star is free for iPhone, iPod Touch and iPad. Only effects like "Crazy Party," "Split Screen," and "Advanced Auto Stop" (for jump cuts and timed-stop motion effects) will cost you. They're $US1 each, if you decide you're so into making music videos that you want to add some next-level touches. And plenty of effects are included for free.
Video Star defaults to shooting in "mirror" mode, so you can see yourself, although you can also use the front-facing camera instead. The app even reminds you to look at the camera, and not the screen, and of course it plays the song back as you film. We found stuff to like everywhere we looked - for instance, the effects preview in real time, so you can see yourself as you shoot.
Once your music video is done, you can upload it to YouTube and share that URL via email, Facebook, and/or Twitter, all within the app.
"What about copyright?", you might ask. Isn't all of that totally illegal? Yes. But it doesn't matter.
Assuming the song you choose is licensed for playback on YouTube, which it probably is, the copyright holders of the song will see a big payday if your video goes viral (the way Chris Brown did for someone else's wedding video). You, on the other hand, get to shoot your video and upload it to YouTube - an act that technically infringes several copyrights, but which is nonetheless almost always fine with all parties. Neat.
Anyway, back to Video Star. After playing around with it for a bit, we're hard-pressed to think of any reason why someone who wants to make "user-generated" music videos and has an iOS device wouldn't download it.